Is an old but new down sleeping bag as good as a recent and new one?

Question

I recently purchased a new western mountaineering sleeping bag (Puma MF) from Moosejaw. Long story short, I found that the bag was manufactured more than 4 years ago, in 2014, the price tags have faded to yellowish color, and the storage sack (not the compression sack) smells like an old library book.

Naturally, the fact that the bag is 4 years old despite being new throws me off a bit due to the high price hence the high expectation.

The indecision is whether I should return the sleeping bag? The main concern here is the old bag will have a shorter lifespan and provide worse insulation than a recently manufactured counterpart. Please let me know whether my concerns are unfounded.

Answer 1

If the bag was compressed most of the time during the storage it may provide less insulation than a recently produced one.

The other thing is, if the bag has caught mildew, you might not be able to get rid of the smell. Or, if the smell goes away after washing, it may develop again. Check for mildew (image) - if there are any small black or similar dots anywhere, I would return it.

Answer 2

You should consider water repellency.

Down does not hold heat once it is wet. Unlike synthetic fillings. This is particularly true of older down products.

The only real innovation in down technology over the last few years has been the introduction of durable water repellent (DWR) down fills. Down with this treatment tends to repel water and is warmer when damp or wet.

Your year is right on the cusp of whether the down in the bag has been treated for water repellency. Read the specs, that should tell you. If the down is not water repellent, you might want to try to return it and get one that is for the same money.